Performance Example

Optimize TeeGrid for maximum rendering speed and responsiveness

Overview

TeeGrid is highly optimized for performance, but there are several techniques to maximize speed, especially with large datasets or complex formatting.

Rendering Engines

TeeGrid supports multiple rendering engines with different performance characteristics.

GDI+ (Default)

uses
  VCLTee.Painter.GdiPlus;

procedure UseGDIPlus;
begin
  TeeGrid1.Painter := TGdiPlusPainter.Create;
  
  // Optional: Enable/disable anti-aliasing
  TGdiPlusPainter(TeeGrid1.Painter).AntiAlias := True;
end;

GDI (Fastest)

uses
  VCLTee.Painter;

procedure UseGDI;
begin
  // GDI is faster but doesn't support anti-aliasing
  TeeGrid1.Painter := TGdiPainter.Create(TeeGrid1.Canvas);
end;

Skia (RAD Studio 12+)

uses
  VCLTee.Painter.Skia;

procedure UseSkia;
begin
  TeeGrid1.Painter := TSkiaPainter.Create;
  
  // Optional: Enable/disable anti-aliasing
  TSkiaPainter(TeeGrid1.Painter).AntiAlias := True;
end;

Performance Benchmark Demo

From Unit_Test_Speed.pas:

unit Unit_Test_Speed;

interface

uses
  Vcl.Forms, Vcl.StdCtrls, Vcl.ComCtrls, Vcl.ExtCtrls,
  VCLTee.Control, VCLTee.Grid;

type
  TFormSpeed = class(TForm)
    TeeGrid1: TTeeGrid;
    Button1: TButton;
    LabelResult: TLabel;
    ComboGraphics: TComboBox;
    CBAntiAlias: TCheckBox;
    CBFormatting: TCheckBox;
    TrackBar1: TTrackBar;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure ComboGraphicsChange(Sender: TObject);
    procedure CBAntiAliasClick(Sender: TObject);
    procedure CBFormattingClick(Sender: TObject);
    procedure TrackBar1Change(Sender: TObject);
  private
    procedure ClearCosmetics;
    procedure RunBenchmark;
    procedure SetCosmetics;
  end;

implementation

uses
  System.Diagnostics, Tee.GridData.Strings, Tee.Grid.Columns,
  Tee.Painter, Tee.Format,
  VCLTee.Painter, VCLTee.Painter.GdiPlus;

// Create sample data
function Sample_Data: TStringsData;
var
  Row, Column: Integer;
begin
  result := TStringsData.Create(20, 100);
  
  // Fill data
  for Row := 0 to result.Rows - 1 do
  begin
    result[0, Row] := IntToStr(Row);
    for Column := 1 to result.Columns - 1 do
      result[Column, Row] := IntToStr(Column);
  end;
  
  // Headers
  result.Headers[0] := 'Row';
  for Column := 1 to result.Columns - 1 do
    result.Headers[Column] := 'Col' + IntToStr(Column);
end;

procedure TFormSpeed.FormCreate(Sender: TObject);
begin
  TeeGrid1.Data := Sample_Data;
  SetCosmetics;
end;

// Switch rendering engine
procedure TFormSpeed.ComboGraphicsChange(Sender: TObject);
begin
  case ComboGraphics.ItemIndex of
    0: TeeGrid1.Painter := TGdiPlusPainter.Create;
    1: TeeGrid1.Painter := TGdiPainter.Create(TeeGrid1.Canvas);
    // 2: TeeGrid1.Painter := TSkiaPainter.Create;  // RAD 12+
  end;
  
  CBAntiAlias.Enabled := not (TeeGrid1.Painter is TGdiPainter);
end;

procedure TFormSpeed.CBAntiAliasClick(Sender: TObject);
begin
  if TeeGrid1.Painter is TGdiPlusPainter then
    TGdiPlusPainter(TeeGrid1.Painter).AntiAlias := CBAntiAlias.Checked;
end;

procedure TFormSpeed.CBFormattingClick(Sender: TObject);
begin
  if CBFormatting.Checked then
    SetCosmetics
  else
    ClearCosmetics;
end;

procedure TFormSpeed.TrackBar1Change(Sender: TObject);
begin
  TeeGrid1.Rows.Spacing.Value := TrackBar1.Position;
end;

procedure TFormSpeed.SetCosmetics;
begin
  // Text alignment
  TeeGrid1.Columns[2].TextAlignment := TColumnTextAlign.Custom;
  TeeGrid1.Columns[2].TextAlign.Horizontal := THorizontalAlign.Center;
  
  TeeGrid1.Columns[3].TextAlignment := TColumnTextAlign.Custom;
  TeeGrid1.Columns[3].TextAlign.Horizontal := THorizontalAlign.Right;
  
  // Font styles
  TeeGrid1.Columns[4].ParentFormat := False;
  TeeGrid1.Columns[4].Format.Font.Style := [TFontStyle.fsBold];
  
  TeeGrid1.Columns[5].ParentFormat := False;
  TeeGrid1.Columns[5].Format.Font.Style := [TFontStyle.fsItalic];
  
  // Background color
  TeeGrid1.Columns[8].ParentFormat := False;
  TeeGrid1.Columns[8].Format.Brush.Show;
  TeeGrid1.Columns[8].Format.Brush.Color := clWebBisque;
  
  // Font color
  TeeGrid1.Columns[9].ParentFormat := False;
  TeeGrid1.Columns[9].Format.Font.Color := clBlue;
  
  // Custom row height
  TeeGrid1.Rows.Heights[20] := 40;
end;

procedure TFormSpeed.ClearCosmetics;
var
  Column: TColumn;
begin
  for Column in TeeGrid1.Columns do
  begin
    Column.ParentFormat := True;
    Column.TextAlignment := TColumnTextAlign.Automatic;
  end;
  
  TeeGrid1.Rows.ResetHeights;
end;

// Benchmark: scroll through all cells
procedure TFormSpeed.RunBenchmark;
var
  Row: Integer;
  Column: TColumn;
begin
  for Row := 0 to TeeGrid1.Data.Count - 1 do
    for Column in TeeGrid1.Columns do
    begin
      TeeGrid1.Selected.Column := Column;
      TeeGrid1.Selected.Row := Row;
    end;
end;

procedure TFormSpeed.Button1Click(Sender: TObject);
var
  t1: TStopwatch;
begin
  ComboGraphics.Enabled := False;
  try
    TeeGrid1.SetFocus;
    
    t1 := TStopwatch.StartNew;
    RunBenchmark;
    
    LabelResult.Caption := 'Time: ' + IntToStr(t1.ElapsedMilliseconds) + ' msec';
  finally
    ComboGraphics.Enabled := True;
  end;
end;

end.

Performance Optimization Techniques

1. Use GDI for Maximum Speed

// Fastest rendering, no anti-aliasing
TeeGrid1.Painter := TGdiPainter.Create(TeeGrid1.Canvas);

2. Disable Anti-Aliasing

if TeeGrid1.Painter is TGdiPlusPainter then
  TGdiPlusPainter(TeeGrid1.Painter).AntiAlias := False;

3. Minimize Custom Formatting

// Each custom format requires additional processing
// Avoid per-cell formatting for large datasets

// Good: Column-level formatting
TeeGrid1.Columns[0].Format.Font.Style := [fsBold];

// Slower: Cell-level formatting (use sparingly)
TeeGrid1.CellFormat.AddCell(10, 20);
TeeGrid1.CellFormat.Cell[10, 20].Format.Brush.Color := clYellow;

4. Reduce Row Spacing

// More compact = fewer rows visible = faster rendering
TeeGrid1.Rows.Spacing.Value := 0;

5. Disable Automatic Row Heights

// Much faster for large datasets
TeeGrid1.Rows.Height.Automatic := False;
TeeGrid1.Rows.Height.Value := 24;  // Fixed height

6. Use Virtual Mode with Default Width

uses
  Tee.GridData.Strings;

// Specify default column width to avoid calculation
Data := TVirtualModeData.Create(
  ColumnCount,
  RowCount,
  60  // Default width - prevents OnGetValue calls for width calculation
);

7. Reduce Mouse Activity

uses
  Tee.Grid;

// Only respond to mouse down/up, not move
TeeGrid1.Grid.MouseActivity := [TGridMouseSense.Down, TGridMouseSense.Up];

8. Disable Grid Lines

// Slightly faster without grid lines
TeeGrid1.Rows.RowLines.Hide;
TeeGrid1.Columns.Visible.Lines := False;

9. Batch Updates

// Disable repaints during updates
TeeGrid1.BeginUpdate;
try
  // Make many changes
  for i := 0 to 100 do
    TeeGrid1.Columns[i].Width.Value := 50;
finally
  TeeGrid1.EndUpdate;  // Single repaint
end;

10. Database Performance

uses
  Data.DB;

// Disable controls during bulk operations
ClientDataSet1.DisableControls;
try
  // Add many records
  for i := 1 to 10000 do
    ClientDataSet1.AppendRecord([...]);
finally
  ClientDataSet1.EnableControls;
end;

Large Dataset Strategies

Virtual Data for Millions of Rows

uses
  Tee.GridData.Strings;

// Can handle millions of rows efficiently
Data := TVirtualModeData.Create(100, 1000000, 60);
Data.OnGetValue := GetValue;
TeeGrid1.Data := Data;

Database Paging

// Instead of loading all rows, use paging
Query.SQL.Text := 'SELECT * FROM LargeTable LIMIT 1000';
Query.Open;
TeeGrid1.DataSource := Query;

// Implement load-more functionality

Lazy Loading

// Load detail data only when needed
procedure GetDetailData(const Sender: TExpanderRender;
  const ARow: Integer; out AData: TObject);
begin
  // Data loaded on demand when row is expanded
  AData := LoadDetailData(ARow);
end;

Benchmarking

Measure Rendering Performance

uses
  System.Diagnostics;

procedure BenchmarkRendering;
var
  sw: TStopwatch;
begin
  sw := TStopwatch.StartNew;
  
  // Force full repaint
  TeeGrid1.Invalidate;
  Application.ProcessMessages;
  
  ShowMessage(Format('Render time: %d ms', [sw.ElapsedMilliseconds]));
end;

Measure Scrolling Performance

procedure BenchmarkScrolling;
var
  sw: TStopwatch;
  i: Integer;
begin
  sw := TStopwatch.StartNew;
  
  for i := 0 to TeeGrid1.Data.Count - 1 do
  begin
    TeeGrid1.Selected.Row := i;
    Application.ProcessMessages;
  end;
  
  ShowMessage(Format('Scroll time: %d ms', [sw.ElapsedMilliseconds]));
end;

Performance Comparison

Typical rendering times for 20 columns x 100 rows:

Configuration	Time (ms)	Notes
GDI, no formatting	~50	Fastest
GDI+, no AA, no formatting	~80	Good balance
GDI+ with AA	~120	Smooth appearance
GDI+ with AA + formatting	~200	Custom styles
Skia with AA	~100	Modern rendering

Actual performance depends on hardware, data complexity, and formatting.

Memory Optimization

Use Virtual Mode

// Constant memory usage regardless of row count
Data := TVirtualModeData.Create(10, 10000000);  // 10M rows!

Free Unused Resources

procedure TForm1.FormDestroy(Sender: TObject);
begin
  // Free data if manually created
  if Data <> nil then
    Data.Free;
  
  // Clear grid
  TeeGrid1.Data := nil;
end;

Avoid Memory Leaks

// Bad: Memory leak
TeeGrid1.Data := TVirtualArrayData<TPerson>.Create(MyArray);
TeeGrid1.Data := TVirtualArrayData<TPerson>.Create(OtherArray);  // Leaks first data!

// Good: Free old data first
if TeeGrid1.Data <> nil then
  TeeGrid1.Data.Free;
TeeGrid1.Data := TVirtualArrayData<TPerson>.Create(MyArray);

Best Practices Summary

1. Choose the right renderer for your needs (GDI for speed, GDI+/Skia for quality)
2. Disable anti-aliasing unless smooth text is critical
3. Use fixed row heights when possible
4. Minimize custom formatting for large datasets
5. Specify default column width in virtual mode
6. Use virtual rendering for very large datasets
7. Batch updates to avoid multiple repaints
8. Disable mouse move events if not needed
9. Profile your application to find bottlenecks
10. Test with realistic data volumes

When Performance Matters Most

• Datasets with 10,000+ rows
• Real-time data updates
• Embedded/mobile devices
• Remote desktop scenarios
• Older hardware
• Complex custom rendering

Next Steps

• Explore Virtual Mode for large datasets
• Learn about Database Grid optimization
• See Themes for appearance customization

Related Examples

• Virtual Mode
• Database Grid
• Basic Grid